<?php
/**
  * wechat php test
  */

//define your token
define("TOKEN", "4297f44b13955235245b2497399d7a93");
$wechatObj = new wechatCallbackapiTest();
$wechatObj->responseMsg();

class wechatCallbackapiTest{

	public function valid(){
        $echoStr = $_GET["echostr"];
        //valid signature , option
        if($this->checkSignature()){
        	echo $echoStr;
        	exit;
        }
    }

    public function log($data){
        file_put_contents("data.log", $data,FILE_APPEND);
    }

    public function responseMsg(){
		//get post data, May be due to the different environments
		$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];
        $this->log($postStr);
      	//extract post data
		if (!empty($postStr)){
                /* libxml_disable_entity_loader is to prevent XML eXternal Entity Injection,
                   the best way is to check the validity of xml by yourself */
                libxml_disable_entity_loader(true);
              	$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);
                $fromUsername = $postObj->FromUserName;
                $toUsername = $postObj->ToUserName;
                $tyle = $postObj->MsgType;
                $keyword = trim($postObj->Content);
                $time = time();
                $textTpl = "<xml>
							<ToUserName><![CDATA[%s]]></ToUserName>
							<FromUserName><![CDATA[%s]]></FromUserName>
							<CreateTime>%s</CreateTime>
							<MsgType><![CDATA[%s]]></MsgType>
							<Content><![CDATA[%s]]></Content>
							<FuncFlag>0</FuncFlag>
							</xml>";  
                if($tyle=="event" && $postObj->Event=="subscribe"){
                    $msgType = "text";
                    $contentStr = "欢迎关注!";
                    $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
                    echo $resultStr;
                }           
				if($keyword=="新安"){
              		$msgType = "text";
                    $contentStr = '<a href="https://www.baidu.com/">帅哥点我啊！</a>';
                	$resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, $msgType, $contentStr);
                	echo $resultStr;
                }

                $articles = array(
                    array(
                        "Title"=>"百度",
                        "Description"=>"百度一下",
                        "PicUrl"=>"https://www.baidu.com/img/bd_logo1.png",
                        "Url"=>"https://www.baidu.com/",
                    ),
                    array(
                        "Title"=>"新安",
                        "Description"=>"新安人才网",
                        "PicUrl"=>"http://www.goodjobs.cn/images/logo.gif",
                        "Url"=>"http://www.goodjobs.cn/",
                    )
                );
                if($keyword=="大尺度"){
                    $textTpl = "<xml>
                        <ToUserName><![CDATA[%s]]></ToUserName>
                        <FromUserName><![CDATA[%s]]></FromUserName>
                        <CreateTime>%s</CreateTime>
                        <MsgType><![CDATA[news]]></MsgType>
                        <ArticleCount>%s</ArticleCount>
                        <Articles>";
                    foreach ($articles as $a) {
                    $textTpl .= "<item>
                        <Title><![CDATA[".$a['Title']."]]></Title> 
                        <Description><![CDATA[".$a['Description']."]]></Description>
                        <PicUrl><![CDATA[".$a['PicUrl']."]]></PicUrl>
                        <Url><![CDATA[".$a['Url']."]]></Url>
                        </item>";
                    }
                    $textTpl .= "</Articles>
                    </xml>";
                    $resultStr = sprintf($textTpl, $fromUsername, $toUsername, $time, count($articles));
                    echo $resultStr;
                }
        }else {
        	echo ""; 
        	exit;
        }
    }
		
	private function checkSignature(){
        // you must define TOKEN by yourself
        if (!defined("TOKEN")) {
            throw new Exception('TOKEN is not defined!');
        }
        
        $signature = $_GET["signature"];
        $timestamp = $_GET["timestamp"];
        $nonce = $_GET["nonce"];
        		
		$token = TOKEN;
		$tmpArr = array($token, $timestamp, $nonce);
        // use SORT_STRING rule
		sort($tmpArr, SORT_STRING);
		$tmpStr = implode( $tmpArr );
		$tmpStr = sha1( $tmpStr );
		
		if( $tmpStr == $signature ){
			return true;
		}else{
			return false;
		}
	}
}

?>